Global Patent Index - EP 0974188 A1

EP 0974188 A1 20000126 - FLYBACK CONVERTER WITH LIMITED OUTPUT POWER

Title (en)

FLYBACK CONVERTER WITH LIMITED OUTPUT POWER

Title (de)

SPERRWANDLER MIT BEGRENZTEM AUSGANGSSTROM

Title (fr)

CONVERTISSEUR INDIRECT A PUISSANCE DE SORTIE LIMITEE

Publication

EP 0974188 A1 20000126 (EN)

Application

EP 99900238 A 19990121

Priority

  • EP 99900238 A 19990121
  • EP 98200275 A 19980130
  • IB 9900093 W 19990121

Abstract (en)

[origin: WO9939427A1] A flyback converter (PS) based on a switcher IC (42) with Pulse Width Modulation control (52) of the switching transistor (54). The pulse width is controlled by changing the input current at the control input (CTL). Under normal operating conditions the voltage at the control input (CTL) is maintained at a fixed level, which voltage also serves as supply voltage for the control unit (52). A charge pump (CP) provides extra charge for the smoothing capacitor (50) at the control input (CTL) when the load (B) would cause the voltage across the smoothing capacitor (50) to collapse under the fixed level, thereby preventing the control unit (52) from entering the auto-restart mode of the switcher IC (42). In this way the flyback converter can be used as a constant power source for charging rechargeable batteries with a working voltage lower than the nominal operating output voltage of the converter.

IPC 1-7

H02M 3/335

IPC 8 full level

H02M 3/28 (2006.01); H02M 3/335 (2006.01); H02M 3/07 (2006.01)

CPC (source: EP US)

H02M 3/33523 (2013.01 - EP US); H02M 3/07 (2013.01 - EP US)

Citation (search report)

See references of WO 9939427A1

Designated contracting state (EPC)

AT DE ES FR GB IT

DOCDB simple family (publication)

WO 9939427 A1 19990805; CN 1256022 A 20000607; EP 0974188 A1 20000126; JP 2002510460 A 20020402; US 6044002 A 20000328

DOCDB simple family (application)

IB 9900093 W 19990121; CN 99800077 A 19990121; EP 99900238 A 19990121; JP 53909699 A 19990121; US 23631099 A 19990122